Technical Field
The present invention relates to a liquid jet head, a liquid jet apparatus, and a method of manufacturing a liquid jet head, which jets liquid droplets on a recording medium to perform recording.
Related Art
In recent years, liquid jet heads of an ink jet system, which eject ink droplets on a recording sheet or the like to record characters and figures, or which eject a liquid material on a surface of an element substrate to form a functional thin film, have been used. This system supplies a liquid such as the ink or the liquid material from a liquid tank to a channel of a liquid jet head through a supply tube, and applies pressure to the liquid in the channel to eject the liquid through a nozzle communicating into the channel, as droplets. In ejecting the droplets, the system moves the liquid jet head and the recording medium, and records the characters and the figures or forms the functional thin film or a three-dimensional structure having a predetermined shape.
As this sort of liquid jet head, a shear mode-type liquid jet head is known. The shear mode-type liquid jet head has ejection channels and dummy channels alternately formed in a surface of a piezoelectric substrate, and momentarily deforms partitions between the ejection channels and the dummy channels to eject liquid droplets through nozzles communicating into the ejection channels. In recent years, the liquid jet head is required to provide high-quality printing, and the volume of the liquid droplets to be ejected becomes small such as several picoliters. To stably eject such fine liquid droplets, efforts to decrease variation in a liquid droplet amount and ejection speed among the channels have been made.
For example, JP 2001-334657 A describes a shear mode-type liquid jet head. FIG. 17 is a perspective view of a liquid jet head 100 described in JP 2001-334657 A. FIGS. 18A and 18B are diagrams for describing characteristics of the liquid jet head 100. FIG. 18A is a diagram illustrating depths of electrodes 105 from right and left upper ends of channel walls 103, and FIG. 18B is a diagram illustrating an applied voltage. In the liquid jet head 100, the depths of the electrodes 105 for driving the channel wall 103 differs in each channel 104, and variation in ejection of liquid droplets occurs accordingly. Therefore, JP 2001-334657 A describes that the applied voltage is changed according to the depths of the electrodes 105 of each channel 104, so that the variation in ejection of liquid droplets is decreased.